Fig. 2: FTO^rs9939609-A promotes myogenesis most robustly.

a Left: representative images of the FTO^rs9939609-TT-myotubes and FTO^rs9939609-A-myotubes. Myotubes as indicated by immunostaining for MHC (MF20; red). Nuclei were counterstained with DAPI. Scale bars, 200 μm. Right: percentage of fusion index of FTO^rs9939609-TT-myotubes and FTO^rs9939609-A-myotubes (FTO-TT vs. FTO-A, P = 0.02795), n = 3 biologically independent samples. b Left: representative images of FTO^rs9939609-TT-myotubes and FTO^rs9939609-A-myotubes. Myotubes as indicated by immunostaining for MHC (MF20; red). Scale bars, 200 μm. Right: morphological characteristics (myotube length and area) of FTO^rs9939609-TT-myotubes and FTO^rs9939609-A-myotubes (FTO-TT vs. FTO-A, P = 0.01326, P = 0.00943), n = 3 biologically independent samples. c Left: representative images of 2D FTO^rs9939609-TT and FTO^rs9939609-A contractile myotubes. Scale bars, 200 μm. Right: percentage of contractility among FTO^rs9939609-TT-myotubes and FTO^rs9939609-A-myotubes (FTO-TT vs. FTO-A, P = 0.00001), n = 3 biologically independent samples. d Representative images of 3D FTO^rs9939609-TT-organoid and FTO^rs9939609-A-organoid, n = 3 biologically independent samples. Scale bars, 8 mm. e The contraction process of the electrical pulse-stimulated 3D muscle organoids in (d) was recorded using a camera, the average contractile displacement was calculated by ImageJ software and plotted against the pulse number (1-22). f Average contractile displacement plotted against pulse number (301-322) in (d). g Volcano plot of differentially expressed genes in FTO^rs9939609-A-muscle organoids, relative to FTO^rs9939609-TT-muscle organoids. h Gene Ontology (GO) analysis of signatures upregulated in FTO^rs9939609-A-muscle organoids, relative to FTO^rs9939609-TT-muscle organoids. i Gene Ontology (GO) analysis of signatures downregulated in FTO^rs9939609-A-muscle organoids, relative to FTO^rs9939609-TT-muscle organoids. H1 hESC line colored in purple, H7 hESC line colored in light blue and H9 hESC line colored in dark blue. Data are presented as mean + SEM. Data were analyzed using Wald test (g) and hypergeometric test (h, i). P values were calculated by two-tailed unpaired t-test (a-c,e-f). *P < 0.05, **P < 0.01. Source data are provided as a Source Data file.